When imaging with the aid of an X-ray machine, for example with the aid of a computed tomography unit that has an X-ray system with an X-ray source and an X-ray detector, the aim is to design the detection surface of the X-ray detector available for imaging to be as large as possible in order to be able to scan entire organs, such as the heart, of a patient in a revolution of the X-ray system about the patient. Such an X-ray detector, also designated as a flat detector, is generally constructed from a multiplicity of detector modules that are juxtaposed two dimensionally in a row. Each detector module has, for example, a scintillator array and a photodiode array that are aligned with one another and form the detector elements of the detector module. The elements of the scintillator array convert the X-radiation striking them into visible light that is converted by the downstream photodiodes of the photodiode array into electric signals.
Making electric contact with the photodiodes of the detector modules or the detector elements in the case of semiconductor detectors turns out to be particularly problematical in the construction of a flat detector. Whereas in the case of a conventionally constructed X-ray detector in which individual detector modules are arranged in sequence on a circular arc, it is possible to arrange a signal processing electronic system on the side, or a cable serving to make contact with the photodiodes of a detector module can be led away at the side to a printed circuit board having a signal processing electronic system, which is to be gathered from US 2005/0029463 A1, this construction is no longer possible in the case of a flat detector, since free space is no longer present at the side owing to the two dimensional arrangement of the detector modules. It is to be noted in this case that the electronic system to be arranged as close as possible to the detector elements on grounds of measurement and used for processing the measuring signals supplied by the detector elements of the detector modules requires an area that can be two to four times larger than the detection surface of a detector module. It appears necessary for this reason to construct the detector module with the signal processing electronic system in a vertical fashion.
U.S. Pat. No. 6,396,898 B1 describes the construction of a flat detector that has a number of detector modules that are juxtaposed in a row and in each case include a so-called element module. The element modules of the detector are of vertical construction, that is to say the components of an element module comprising scintillators, photodiodes, a substrate with a signal processing electronic system and a module base plate are arranged vertically one above another.
In such a vertical construction of a detector module, it is, however, necessary to pay heed to a good heat dissipation, since otherwise the considerable development of heat during operation of the signal processing electronic system can cause damage to the electronic system.